1. Field of the Invention
This invention relates generally to improvements in a foot-operated bass drum pedal and more particularly to a bass drum pedal with a cam system wherein a user may adjust the eccentricity of the cam system to thereby obtain an optimized drum pedal for a user's performance.
2. Description of Related Art
A drummer plays the bass drum by pressing down the drum pedal. Each drummer needs his own drum pedal suitable to him because each drummer has different playing style and physical condition.
The primary factors that determine the overall feels of the drum pedal to the drummer himself and the performance characteristics are an impact force and a restoring force. In this description, the impact force is defined as a force acted on a bass drum head by a beater when the beater strikes the drum head, and the restoring force is defined as a force applied to a foot board by a spring to return the foot board to its original up-position.
A strong impact force enables the drummer to play a powerful performance, and a strong restoring force enables the drummer to play a speedy performance.
With the same stepping force on the foot board, the impact force acted on the drum head by the beater and the restoring force applied to the foot board by the spring depend on the torque arm of the cam system.
When the torque arm of the cam system is long, the impact force acted on the drum head by the beater is strong. But in this case, the restoring force applied to the foot board by the spring thereby returning the foot board to its original up-position is weak. On the contrary, when the torque arm is short, the impact force is weak and the restoring force is strong.
Because the impact force and the restoring force suitable to each drummer might vary, conventional drum pedal companies have provided many kinds of drum pedals, each of which has different torque arm of cam system, thereby permitting the drummers to selectively purchase the suitable one to him. But when a drummer's playing style changes, a drummer must buy a new pedal. And if a drummer intends to try a variety of playing styles, he has to purchase a plurality of drum pedals with different cam features.
Therefore, there's been a need for a drum pedal wherein the torque arm of the cam system is adjustable. A prior art that meets the above need is U.S. Pat. No. 6,172,291.
Said prior art provides a plurality of interchangeable cam members with different shape and radius for selective attachment to the drum pedal sprocket. But it takes a great deal of time to remove a cam member and interchange it with another one, and it is liable to lose the cam members not in use.
The present invention tends to solve the above problems and permits the user to tune the bass drum pedal up more efficiently and precisely to suit the user's style and ability without any risk of missing cam members.